Spark-plug.



J. J. PLATT'.

' SPARK PLUG.

A APPLICATION FILED MAY 24, 1912A 1,088,620. Patented Feb.-24,1914.

2 SHEETS-SHEET l.

, 4 @mue/futon t5 y Qcz/Waff J. J. PLATT.

SPARK PLUG.

JOHN JELLIFF PLATT, OF MILFORD, CONNECTXCUT.

SPARILPLUG.

Specification of Letters Patent.V

Patented Feb. 24, 1914.

Application filed May 24, 1912. Serial No. 699,432.

may be primed to facilitate the starting thereof and to admit of theliash due to the passage of the spark and to the ignition of the gaseous mixture 'being readily observed so that f it may be instantly determined whether the spark is passing or the gaseous mixture exploding.

The invention aims further to provide a spark plug having tubular electrodes which may be utilized as means for conveying the fuel to the enginewhen priming the same or for conveying the flash incident to exf plosion ofthe gaseous mixture to a predetei-mined point for observation or to admit of the introduction of a cleaner whereby the spacebetween the electrodes may be cleared of any carbon or other obstructing matter or which may be used as a blow-off for carrying away any matter tending to foul the electrodes by providing an escape for the air or gaseous mixture on the compression stroke of the piston.

The invention further contemplates novel means for closing the circuit to prevent the formation of a spark during the time that fuel is supplied to the engine for priming the same, with the result of preventing premature explosion.

` The invention further proposes to combine with a. spark plug means whereby the circuit may be interrupted to admit of the sparkbeing observed provided the ignition system is in proper working condition so that any cylinder of a multiple engine missing by reason of failure of the spark may be quickly determined, with the result that the diticulty being located may be quickly remedied.

The invention also contemplates novel means for priming the engine, said means being readily accessible to be operated on a ,moments notice to admit of supplying gasolene or other liquid fuel to the engine forA priming the same when the engine is diiiicult of starting, as in cold weather.

The invention 'consists of the novel features, details of construction and combination of parts, which hereinafter will be more particularly set forth, illustrated in the accompanying drawings, and 'pointed out in the appended claims.

Referring to the drawings, forming a part of the specification, Figure l is a vertical central section of'a spark plug embodying the invention. Fig. 2 is a side view of the shell or bushing which is adapted to be fitted to the cylinder of the engine. Fig. 3 is a sectional detail of the shell forming one member of the breech-block between the two parts of the spark plug.` Fig. 4 is a detail view in perspective of the spark gap body,k having the switch in position by means of which the electric circuit may be broken to admit of observing the spark. Fig. 5 is a horizontal section on the line -a' of Fig. 1. Fig. 6 is a horizontal section on the line yug/ of Fig. l.

Corresponding and like partsV are referred to in the following description, and indicated in all the views of the drawings, by the same reference characters.

The spark plug illustrated is of the breech-block type and comprises two parts which are readily separable by means of a partial rotation of one of such parts.

The part to be attached to the cylinder of the engine is indicated at 41 and consists of a shell or bushing. rlhe lower end of the shell l1 is threaded to admit of its screwing into a threaded opening formed in a part of the engine. The upper part of the shell 41 is formed upon its outer side with screwthread sections 37, which are adapted to engage with screwthrea'd sections 37 upon the inner side of a shell 36,' thereby forming the breech-block between the two parts of the spark plug. The screwthread sections 37 are separated by plain portions of such a width as te receive the screwthread sections 3T of the shell 3G, thereby admitting of slipping of one shell upon the other when the screwthread sections of one are brought opposite the plain portion between the screwthread sections of the other. After the shells 36 and 4l have been brought together they are locked by a relative turning of one upon the other which brings the screwthread sections 37 and 3'?t into engagement, said screwthread serving to draw the parts together so as to insure the formation of a close joint between the parts. The opening in the lower portion of the shell l1 is straight, whereas the opening in the upper portion of the shell is flared to receive a tapered part 36a of the shell 36. A cross bar T is providedat the lower end of' the lower end of the electrode after the jam put 38 has been loosened.

lThe upper or detachable partof the spark' plug comprises the shell 36, which is formed with a tapered portion 36"1 of such a size and taper as to fit within the tapered open- ,ing in the upper part of the shell 4:1. The

shell 36 has its upper portion evternalljT threaded to receive a lock nut 35 and has an angular portion 36" at the base of' the upper threaded portion to receive a handle by means of .which the upper part of the spark plug is turned when making -or breaking the breech-block. rlhe inner end of the han die 42 has an angular opening to receive the angular' part 36 and is confined between the lcclr nut 35 and the shoulder formed at the base of the angular portion 361. The tapered part 36L of the shell 36 has its lower end contracted to form an inner shoulder 36C, which engages and supports a body 32' of insulating material, such` as porcelain or other vitreousl material. A gland 33 is threaded into the upper portion of the shell 3G and secures the body 32 therein.

rl`he h andle 12 has its outer portion hollow and is closed at its outer end by means ot' a cap 43. The spacewithin the-handle is intended chiefly to ('f-ntain a cleaner 44; by-

. thefbody 32 is of greater diameter than the tpening formed 1n the upper portion and 1s ada ptedi lo receive the ends of the two electrodes andv the lower enlarged portion' of' the uppcr'lo'r high tensionelectrode 50, rihe -ous mixture being seen.

middle portion of the body 32 is slightly enlarged to form upper and lower shoulders, the latter engaging the shoulder 36 and the gland 33 engaging the upper shoulder.

The high tension electrode 50 is tubular and its lower portion is enlarged and is litted within the enlarged opening 32a. The electrode 50 is of a length to project some distance beyond the end of the body 32, the projecting portion being externally threaded. A ferrule 30 is fitted upon the upper end of the body l32 and is threaded on the projecting end of the electrode 50. A plate 29 is' fitted on the projecting end of the electrodeO and is clamped between the 'ferrule 30 and a lock nut 22. A fitting 26 is threaded upon the projecting end of the electrode 50 andv its lower end engages the loelr nut 22. The upper portion of the fitting 26 is recessed to receive a short section 27 of glass tubing, t-he sides .of the recessed portion having observation openings to admit of the flash resulting' from combustion of the gase- The fitting 26 is of, metal andits` lower portion is externally threaded to receive a bushing 51, which has an outer lianve4 atfits lower end to receive and Vsupport the spark gap body 21. A nut 20 iswt-hrea ed upon the fitting 26 and extends over he body 21 and is formed with openings 21n to admit of thefsparl beine readily seen when the circuit is interrupted by means of the switch. The upper end of the fitting 26 is threaded to receive a cup 12.

Packing 17 and 19 is interposed between the ends ot' the' glass tube 27 and the parts 12 and 26 to insure the formation of a tight joint.

minal of the high tension wire. flfliaupper portion olf-the body 21 has a recess 25 in which is arranged a switch 22a having an insulated handle. A contact l is fitted in a part ofthe body separating the annular groove 52 from the recess 25 and is in electrical connection with the washer 211. The switch 22 is adapted to close the circuit through the contact P and whenlmoved to a position to interrupt the circuit results in the torn'lation of a gap across which the .spark jumps, thereby admitting of said spark being observed through the openings i 2l of the part 20. The wall of the body 2l snrrouinling the recess has a slot 2l" through which a part of the sw'itch 22L extends. n

The cup 12 consists of a fitting having recesses in the opposite ends ana a centrally disposed opening est-ablishing communication between said recesses, the lower end of the opening being enlarged to form a seat 12at for a valve 12b, which is adapted to open downwardly and has its stem projecting into the upperrecess and receiving a spring 13 by means of which the valve is seated and normally held closed. The stem ofthe Valve 12b fits loosely within the opening formed in the lower part separating the recesses formed in the ends of the cup 12so that when the valve is unseated a passage is had between the recessed ends of the part 12. A cap 6 is threaded to the upper end of the part 12 and closes the recess thereof. A tube 11 connects with the cap 6 and leads into the recess 14in the upper end of the part 12 so as to convey gasolene or other liquid fuel thereto. A stem- 1 is mounted in the capl 6 in line with the valve 12b and is pressed outwardly by means of a spring 5 interposed between a nut 3 mounted upon the stem 1 and a tubular extension of the cap 6. A plate 4 is mounted upon the stem 1 and is clamped thereto between the nut 3 and acompanion nut 2. Arod 16 is mounted in the parts 4, 6 and 29 in such a mannerv as "to move therein. The lower end of the rod 16 is adapted to make electric eonnection with the lower part of the -spark plug7 thereby closing the circuit between the two velectrodes and preventing the passage of lthrough the plate 4 and receives a nut N upon its upper portion above the plate 4 and a spring 9 below said plate, said spring bef ing supported at its lower end upon a stop 10.- When the stem 1 is pressed inward t0' unseat the valve 12b it at'the same time. .moves the rod 16, thereby bringing it in con- -tact with the lpck nut 85 or breech'part -ofl the plug so' as to close the circuit and thereby prevent the spark between the electrodes' 50 and 39. The vspring 9 forms a yielding connection between the part 4 and the rod 16, thereby admitting of the stem 1 continuing to move after the rod 16 has come in contact with the lock nut 35. A

The tube 11 connects with any suitable 'source for supplying gasolene or other liquid fuel whereby the engine may be primed when required. When the space 14 is supplied rwith gasolene or liquid fuel the latter may pass into the engine through the tubular electrodes 50 and 39 when the valve 12 is unseated, this being accomplished by pressing inward upon the stem 1. At or an in stant before 4the valve 12*D is unseated the circuit is closed by means of the rod 16 coming in contact with theio'ck nut 35, thereby preventing the formation of a spark. The stem` 1v may be operated in any manner, as

'.bypmeansof a shaft53 and aicarn 54, the

latter.- fvorming a part of orsecured to the shaft When the shaft 53 is turned the cam 54 coming in contact with the stem 1 presses the same inward and unseats the valve 12", thereby permitting the liquid fuel to pass from the recess 14 through the electrodesO and 39 into the cylinder of the engine.

The electrodes 50 and 39 Amay be formed of metal tubing of any nature andlmay be provided withv tips of German silver, platinum or other material best adapted to form spark terminals. The flash resulting from combustion of the gaseous mixture may be seen in the part 27, thereby apprising the operator that the engine is working properly. The flash is conveyed to the part 27 through the tubular electrodes. The spark passing between the terminals-of the electrodes may likewise be observed by looking downwardly through the electrodes after either by removing the cup 12 oran equivalent part to the rupper end of the fitting 26. The construction is such as to admit of a cleaner being passed through the electrodes to remove any soot or other fouling vmatter therefrom. yThe cleaner 44 may consist of aslender brush embodying a wire stem and bristles fitted to an end thereof. This cleaner when passed through the electrodes will remove any matter lodging between the terminals of the electrodes without necessitating the separation of the upper part of the spark plug from the part attached' to the cylinder of the engine.

When the valve 12h is unscated and the engine is operated the gaseous mixture may be forced from the cylinder upon the compression stroke of the piston so as to pass through the electrodes and carry off all obstructing matter. 1f preferred the valve 12h mayy be unseated when the gaseous mixture is compressed. in the cylinder. thereby adord ing a quick relief through which the gaseous mixture escapes with a great rush, thereby serving to clear the electrodes of, any fouling matter.

The working of the ignition-system may be determined by looking downwardly through the electrode 50 or by moving the switch 22UL to form a spark gap in the recess 25 of the body 21 so that the spark may be observed through the openings 211 of the lock washer 20. v n

it is to be understood that the tubular electrodes and the spark and flash sight. as also the priming mechanism may be applied lto spark plugs of any varietypwhether of the breech-block type or other'form.

From the foregoing description, taken in connection with the accompanying drawings. the advantages of the construction and of the method of operation will be readily apparent to those skilled in the art to which the invention appertains, and while I have described the principle of operation of the invention, together with t-hedevice which I now consid@ to be the best embodiment thereof, I desire to have it understood that the device shown is merely illustrative, and

that such changes may be made when desired as are within the scope ot the claims appended hereto.

.Having thus described the invention what is claimed as new. iszl. .ln a spark plugr the combination ot a body, elect-redes at the lower end ,et the body, the upper electrode beine' tubular and extending' above the said body, fitting connected with the upper projecting end of the electrode and having a recess in its upper end and an observation opening' in its side leading' into said' recess, and a tube of transparent material seci'lred in the recess ot the tittiue' and in communication with the tubular electrode to admit of' fuel passing therethrough and the spark or iiash duc to ignition beine' viewed through the lateral observation oj'iening'.

2. ln a spark plug the combination ot a body, electrodes carried by the body, the upper electrode being tubular and projecting' tln'o-ugh and above the body, a fitting attached to the projecting' end of the electrode and having a recess in its upper end and an observation opening in a side leading' into the recess, a tube of transparent material secured in the recess of the fitting and in communication with the tubular electrode, a cup attached to the upper end ot the fitting' and securing the sleeve therein, and a valve closing' an opening in the bottom of4 said cup.

3. ln a spark plug the combination of a body, electrodes carried by the body, the upper electrode being' tubular and projectiue' through and above the body, a fitting attached to the projecting end ofthe electrode and having; a recess in its upper end and an observation opening in a side leadino' into the recess, a tube of transparent material securedI in the recess of the fitting and in communication with the tubular electrode,a cup attached to the upper end of the fitting and securing the sleeve therein, a valve closing' an opening in the bottom of said cup, a cap for closing' the cup, a stem slidably mounted in the cap in line with the valve, and a rod having' connection 'with the stem and adapted to short circuit the electrodes preliminary to the'unseating of the valve. v

it. fin a spark plug the combination of a body, electrodes carried by the body, the upper electrode being tubular and projecting through and above the body, a. fitting` attached to thel projecting' end ot the electrode and having' a recess in its upper end and au observation opening iu` a. side leadiner into the rece. a tube ot trauspart-int material securedin the recess ot the fitting; and in con'nnunication with the tulimlar electrode, a cup attached to the upper end et the litting and. securing` the sleeve therein. a valve closing an opening' in the bottom ot said cup, a cap tor closing the cup, a stem slidably mounted in the cap in line with the valve, a red tor short circuiting the electrodes, and a yieldable connection between said rod and stem to admit oit the continued movement of the latter after the rod has ceased movement a'tter short circuiting the electrodes.

5. In a spark plug` the combination ot a body, electrodes supported by the body, the upper electrode being' tubular, a cup connected with the body and having an opening' in its bottom, a valve for closing the opening of the cup, ay cap for closing the cup. a spring;` actuated stein mounted in the cap and adapted when depressed to unseat the valve, a rod for short circuiting the electrodes, and a yieldable connection between said rod and stein to admit ot the latter having' a continued movement atten the rod has ceased to move after short circuiting' the electrodes. s

6. ln a spark plug' the combination ot a spark ,ajap bodyl ot insulating material having a recess in its upper side, a fixed contact having' its respective ends exposed within the recess and upon the exterior of said body, the outer end being adapted to make electric connection with the conducting' wire, and a switch arranged within the spark gap body and having` electric connection with one of the electrodes ot the plusr and adapted to make connection with the betere mentioned contact.

7.111 a spark plug' the combination ot a spark gap body havingv its upper side formed with a recess and having' a slot in the wall surrounding'A said recess, a ixed contact having its respective ends exposed Within the recess and upon the outside of the said body and adapted to have the conducting1 Wire connected thereto, a switch cooperating with the'xed contact fitted within the recess of the spark lap body and havinf; electric connection with one ot the electrodes ot the spark plug, and. a handle tor operating the switch passing' through the,

slot in the side of said spark gap body.

ln testimony whereof I allix. my signature in presence ot two witnesses.

JOHN JELLIFF PLATT. lViti'iesses lV. J. Simeri-inno, Cmrrono ll. llavr'r. 

